neil / rpms / libblockdev

Forked from rpms/libblockdev a year ago
Clone
Blob Blame History Raw
From 3f9f1fa90a087186dcc96060537543d2685616d8 Mon Sep 17 00:00:00 2001
From: Vojtech Trefny <vtrefny@redhat.com>
Date: Mon, 1 Oct 2018 16:06:42 +0200
Subject: [PATCH 1/2] Use libblkid to check swap status before swapon

libblkid probe is more reliable than our custom check.
---
 configure.ac            |   2 +-
 src/plugins/Makefile.am |   4 +-
 src/plugins/swap.c      | 149 ++++++++++++++++++++++++++++++++--------
 3 files changed, 124 insertions(+), 31 deletions(-)

diff --git a/configure.ac b/configure.ac
index 6285a48..7ac5089 100644
--- a/configure.ac
+++ b/configure.ac
@@ -227,7 +227,7 @@ AS_IF([test "x$with_fs" != "xno"],
               AC_SUBST([PARTED_FS_CFLAGS], [])])],
       [])
 
-AS_IF([test "x$with_fs" != "xno" -o "x$with_crypto" != "xno"],
+AS_IF([test "x$with_fs" != "xno" -o "x$with_crypto" != "xno" -o "x$with_swap" != "xno"],
       [LIBBLOCKDEV_PKG_CHECK_MODULES([BLKID], [blkid >= 2.23.0])
       # older versions of libblkid don't support BLKID_SUBLKS_BADCSUM so let's just
       # define it as 0 (neutral value for bit combinations of flags)
diff --git a/src/plugins/Makefile.am b/src/plugins/Makefile.am
index e7b4bf0..6219a40 100644
--- a/src/plugins/Makefile.am
+++ b/src/plugins/Makefile.am
@@ -149,8 +149,8 @@ libbd_nvdimm_la_SOURCES = nvdimm.c nvdimm.h check_deps.c check_deps.h
 endif
 
 if WITH_SWAP
-libbd_swap_la_CFLAGS = $(GLIB_CFLAGS) -Wall -Wextra -Werror
-libbd_swap_la_LIBADD = $(GLIB_LIBS) ${builddir}/../utils/libbd_utils.la
+libbd_swap_la_CFLAGS = $(GLIB_CFLAGS) $(BLKID_CFLAGS) -Wall -Wextra -Werror
+libbd_swap_la_LIBADD = $(GLIB_LIBS) $(BLKID_LIBS) ${builddir}/../utils/libbd_utils.la
 libbd_swap_la_LDFLAGS = -L${srcdir}/../utils/ -version-info 2:0:0 -Wl,--no-undefined
 libbd_swap_la_CPPFLAGS = -I${builddir}/../../include/
 libbd_swap_la_SOURCES = swap.c swap.h check_deps.c check_deps.h
diff --git a/src/plugins/swap.c b/src/plugins/swap.c
index bc52637..bfe653f 100644
--- a/src/plugins/swap.c
+++ b/src/plugins/swap.c
@@ -21,6 +21,8 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/swap.h>
+#include <fcntl.h>
+#include <blkid.h>
 #include <blockdev/utils.h>
 
 #include "swap.h"
@@ -179,13 +181,14 @@ gboolean bd_swap_mkswap (const gchar *device, const gchar *label, const BDExtraA
  * Tech category: %BD_SWAP_TECH_SWAP-%BD_SWAP_TECH_MODE_ACTIVATE_DEACTIVATE
  */
 gboolean bd_swap_swapon (const gchar *device, gint priority, GError **error) {
-    GIOChannel *dev_file = NULL;
-    GIOStatus io_status = G_IO_STATUS_ERROR;
-    GError *tmp_error = NULL;
-    gsize num_read = 0;
-    gchar dev_status[11];
-    dev_status[10] = '\0';
-    gint page_size;
+    blkid_probe probe = NULL;
+    gint fd = 0;
+    gint status = 0;
+    guint n_try = 0;
+    const gchar *value = NULL;
+    gint64 status_len = 0;
+    gint64 swap_pagesize = 0;
+    gint64 sys_pagesize = 0;
     gint flags = 0;
     gint ret = 0;
     guint64 progress_id = 0;
@@ -198,53 +201,143 @@ gboolean bd_swap_swapon (const gchar *device, gint priority, GError **error) {
 
     bd_utils_report_progress (progress_id, 0, "Analysing the swap device");
     /* check the device if it is an activatable swap */
-    dev_file = g_io_channel_new_file (device, "r", error);
-    if (!dev_file) {
-        /* error is already populated */
+    probe = blkid_new_probe ();
+    if (!probe) {
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Failed to create a new probe");
         bd_utils_report_finished (progress_id, (*error)->message);
         return FALSE;
     }
 
-    page_size = getpagesize ();
-    page_size = MAX (2048, page_size);
-    io_status = g_io_channel_seek_position (dev_file, page_size - 10, G_SEEK_SET, &tmp_error);
-    if (io_status != G_IO_STATUS_NORMAL) {
+    fd = open (device, O_RDONLY|O_CLOEXEC);
+    if (fd == -1) {
         g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
-                     "Failed to determine device's state: %s", tmp_error->message);
-        g_clear_error (&tmp_error);
-        g_io_channel_shutdown (dev_file, FALSE, &tmp_error);
+                     "Failed to open the device '%s'", device);
         bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
         return FALSE;
     }
 
-    io_status = g_io_channel_read_chars (dev_file, dev_status, 10, &num_read, &tmp_error);
-    if ((io_status != G_IO_STATUS_NORMAL) || (num_read != 10)) {
+    /* we may need to try mutliple times with some delays in case the device is
+       busy at the very moment */
+    for (n_try=5, status=-1; (status != 0) && (n_try > 0); n_try--) {
+        status = blkid_probe_set_device (probe, fd, 0, 0);
+        if (status != 0)
+            g_usleep (100 * 1000); /* microseconds */
+    }
+    if (status != 0) {
         g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
-                     "Failed to determine device's state: %s", tmp_error->message);
-        g_clear_error (&tmp_error);
-        g_io_channel_shutdown (dev_file, FALSE, &tmp_error);
-        g_clear_error (&tmp_error);
+                     "Failed to create a probe for the device '%s'", device);
         bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
         return FALSE;
     }
 
-    g_io_channel_shutdown (dev_file, FALSE, &tmp_error);
-    g_clear_error (&tmp_error);
+    blkid_probe_enable_superblocks (probe, 1);
+    blkid_probe_set_superblocks_flags (probe, BLKID_SUBLKS_TYPE | BLKID_SUBLKS_MAGIC);
 
-    if (g_str_has_prefix (dev_status, "SWAP-SPACE")) {
+    /* we may need to try mutliple times with some delays in case the device is
+       busy at the very moment */
+    for (n_try=5, status=-1; !(status == 0 || status == 1) && (n_try > 0); n_try--) {
+        status = blkid_do_safeprobe (probe);
+        if (status < 0)
+            g_usleep (100 * 1000); /* microseconds */
+    }
+    if (status < 0) {
+        /* -1 or -2 = error during probing*/
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Failed to probe the device '%s'", device);
+        bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    } else if (status == 1) {
+        /* 1 = nothing detected */
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "No superblock detected on the device '%s'", device);
+        bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    }
+
+    status = blkid_probe_lookup_value (probe, "TYPE", &value, NULL);
+    if (status != 0) {
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Failed to get format type for the device '%s'", device);
+        bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    }
+
+    if (g_strcmp0 (value, "swap") != 0) {
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Device '%s' is not formatted as swap", device);
+        bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    }
+
+    status = blkid_probe_lookup_value (probe, "SBMAGIC", &value, NULL);
+    if (status != 0) {
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Failed to get swap status on the device '%s'", device);
+        bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    }
+
+    if (g_strcmp0 (value, "SWAP-SPACE") == 0) {
         g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE,
                      "Old swap format, cannot activate.");
         bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
         return FALSE;
-    } else if (g_str_has_prefix (dev_status, "S1SUSPEND") || g_str_has_prefix (dev_status, "S2SUSPEND")) {
+    } else if (g_strcmp0 (value, "S1SUSPEND") == 0 || g_strcmp0 (value, "S2SUSPEND") == 0) {
         g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE,
                      "Suspended system on the swap device, cannot activate.");
         bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
         return FALSE;
-    } else if (!g_str_has_prefix (dev_status, "SWAPSPACE2")) {
+    } else if (g_strcmp0 (value, "SWAPSPACE2") != 0) {
         g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE,
                      "Unknown swap space format, cannot activate.");
         bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    }
+
+    status_len = (gint64) strlen (value);
+
+    status = blkid_probe_lookup_value (probe, "SBMAGIC_OFFSET", &value, NULL);
+    if (status != 0 || !value) {
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Failed to get swap status on the device '%s'", device);
+        bd_utils_report_finished (progress_id, (*error)->message);
+        blkid_free_probe (probe);
+        close (fd);
+        return FALSE;
+    }
+
+    swap_pagesize = status_len + g_ascii_strtoll (value, (char **)NULL, 10);
+
+    blkid_free_probe (probe);
+    close (fd);
+
+    sys_pagesize = getpagesize ();
+
+    if (swap_pagesize != sys_pagesize) {
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+                     "Swap format pagesize (%"G_GINT64_FORMAT") and system pagesize (%"G_GINT64_FORMAT") don't match",
+                     swap_pagesize, sys_pagesize);
+        bd_utils_report_finished (progress_id, (*error)->message);
         return FALSE;
     }
 
-- 
2.17.1


From f6508829e7cac138e4961a1c3ef6170d6f67bfd9 Mon Sep 17 00:00:00 2001
From: Vojtech Trefny <vtrefny@redhat.com>
Date: Thu, 4 Oct 2018 08:07:55 +0200
Subject: [PATCH 2/2] Add error codes and Python exceptions for swapon fails

We need to be able to tell why swapon failed so our users can
decide what to do.
---
 src/lib/plugin_apis/swap.api        |  4 ++++
 src/plugins/swap.c                  | 10 +++++-----
 src/plugins/swap.h                  |  4 ++++
 src/python/gi/overrides/BlockDev.py | 19 +++++++++++++++++--
 tests/swap_test.py                  | 13 +++++++++++++
 5 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/src/lib/plugin_apis/swap.api b/src/lib/plugin_apis/swap.api
index d0906fe..3fcc0e5 100644
--- a/src/lib/plugin_apis/swap.api
+++ b/src/lib/plugin_apis/swap.api
@@ -10,6 +10,10 @@ typedef enum {
     BD_SWAP_ERROR_UNKNOWN_STATE,
     BD_SWAP_ERROR_ACTIVATE,
     BD_SWAP_ERROR_TECH_UNAVAIL,
+    BD_SWAP_ERROR_ACTIVATE_OLD,
+    BD_SWAP_ERROR_ACTIVATE_SUSPEND,
+    BD_SWAP_ERROR_ACTIVATE_UNKNOWN,
+    BD_SWAP_ERROR_ACTIVATE_PAGESIZE,
 } BDSwapError;
 
 typedef enum {
diff --git a/src/plugins/swap.c b/src/plugins/swap.c
index bfe653f..28db6f3 100644
--- a/src/plugins/swap.c
+++ b/src/plugins/swap.c
@@ -292,21 +292,21 @@ gboolean bd_swap_swapon (const gchar *device, gint priority, GError **error) {
     }
 
     if (g_strcmp0 (value, "SWAP-SPACE") == 0) {
-        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE,
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE_OLD,
                      "Old swap format, cannot activate.");
         bd_utils_report_finished (progress_id, (*error)->message);
         blkid_free_probe (probe);
         close (fd);
         return FALSE;
     } else if (g_strcmp0 (value, "S1SUSPEND") == 0 || g_strcmp0 (value, "S2SUSPEND") == 0) {
-        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE,
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE_SUSPEND,
                      "Suspended system on the swap device, cannot activate.");
         bd_utils_report_finished (progress_id, (*error)->message);
         blkid_free_probe (probe);
         close (fd);
         return FALSE;
     } else if (g_strcmp0 (value, "SWAPSPACE2") != 0) {
-        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE,
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE_UNKNOWN,
                      "Unknown swap space format, cannot activate.");
         bd_utils_report_finished (progress_id, (*error)->message);
         blkid_free_probe (probe);
@@ -318,7 +318,7 @@ gboolean bd_swap_swapon (const gchar *device, gint priority, GError **error) {
 
     status = blkid_probe_lookup_value (probe, "SBMAGIC_OFFSET", &value, NULL);
     if (status != 0 || !value) {
-        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE_PAGESIZE,
                      "Failed to get swap status on the device '%s'", device);
         bd_utils_report_finished (progress_id, (*error)->message);
         blkid_free_probe (probe);
@@ -334,7 +334,7 @@ gboolean bd_swap_swapon (const gchar *device, gint priority, GError **error) {
     sys_pagesize = getpagesize ();
 
     if (swap_pagesize != sys_pagesize) {
-        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_UNKNOWN_STATE,
+        g_set_error (error, BD_SWAP_ERROR, BD_SWAP_ERROR_ACTIVATE_PAGESIZE,
                      "Swap format pagesize (%"G_GINT64_FORMAT") and system pagesize (%"G_GINT64_FORMAT") don't match",
                      swap_pagesize, sys_pagesize);
         bd_utils_report_finished (progress_id, (*error)->message);
diff --git a/src/plugins/swap.h b/src/plugins/swap.h
index a01c873..9947bad 100644
--- a/src/plugins/swap.h
+++ b/src/plugins/swap.h
@@ -12,6 +12,10 @@ typedef enum {
     BD_SWAP_ERROR_UNKNOWN_STATE,
     BD_SWAP_ERROR_ACTIVATE,
     BD_SWAP_ERROR_TECH_UNAVAIL,
+    BD_SWAP_ERROR_ACTIVATE_OLD,
+    BD_SWAP_ERROR_ACTIVATE_SUSPEND,
+    BD_SWAP_ERROR_ACTIVATE_UNKNOWN,
+    BD_SWAP_ERROR_ACTIVATE_PAGESIZE,
 } BDSwapError;
 
 typedef enum {
diff --git a/src/python/gi/overrides/BlockDev.py b/src/python/gi/overrides/BlockDev.py
index c2ef2f4..e608887 100644
--- a/src/python/gi/overrides/BlockDev.py
+++ b/src/python/gi/overrides/BlockDev.py
@@ -1031,7 +1031,17 @@ __all__.append("MpathError")
 
 class SwapError(BlockDevError):
     pass
-__all__.append("SwapError")
+class SwapActivateError(SwapError):
+    pass
+class SwapOldError(SwapActivateError):
+    pass
+class SwapSuspendError(SwapActivateError):
+    pass
+class SwapUnknownError(SwapActivateError):
+    pass
+class SwapPagesizeError(SwapActivateError):
+    pass
+__all__.extend(("SwapError", "SwapActivateError", "SwapOldError", "SwapSuspendError", "SwapUnknownError", "SwapPagesizeError"))
 
 class KbdError(BlockDevError):
     pass
@@ -1070,6 +1080,11 @@ __all__.append("BlockDevNotImplementedError")
 not_implemented_rule = XRule(GLib.Error, re.compile(r".*The function '.*' called, but not implemented!"), None, BlockDevNotImplementedError)
 
 fs_nofs_rule = XRule(GLib.Error, None, 3, FSNoFSError)
+swap_activate_rule = XRule(GLib.Error, None, 1, SwapActivateError)
+swap_old_rule = XRule(GLib.Error, None, 3, SwapOldError)
+swap_suspend_rule = XRule(GLib.Error, None, 4, SwapSuspendError)
+swap_unknown_rule = XRule(GLib.Error, None, 5, SwapUnknownError)
+swap_pagesize_rule = XRule(GLib.Error, None, 6, SwapPagesizeError)
 
 btrfs = ErrorProxy("btrfs", BlockDev, [(GLib.Error, BtrfsError)], [not_implemented_rule])
 __all__.append("btrfs")
@@ -1092,7 +1107,7 @@ __all__.append("md")
 mpath = ErrorProxy("mpath", BlockDev, [(GLib.Error, MpathError)], [not_implemented_rule])
 __all__.append("mpath")
 
-swap = ErrorProxy("swap", BlockDev, [(GLib.Error, SwapError)], [not_implemented_rule])
+swap = ErrorProxy("swap", BlockDev, [(GLib.Error, SwapError)], [not_implemented_rule, swap_activate_rule, swap_old_rule, swap_suspend_rule, swap_unknown_rule, swap_pagesize_rule])
 __all__.append("swap")
 
 kbd = ErrorProxy("kbd", BlockDev, [(GLib.Error, KbdError)], [not_implemented_rule])
diff --git a/tests/swap_test.py b/tests/swap_test.py
index 05d0c19..395fdf5 100644
--- a/tests/swap_test.py
+++ b/tests/swap_test.py
@@ -97,6 +97,19 @@ class SwapTestCase(SwapTest):
         _ret, out, _err = run_command("blkid -ovalue -sLABEL -p %s" % self.loop_dev)
         self.assertEqual(out, "BlockDevSwap")
 
+    def test_swapon_pagesize(self):
+        """Verify that activating swap with different pagesize fails"""
+
+        # create swap with 64k pagesize
+        ret, out, err = run_command("mkswap --pagesize 65536 %s" % self.loop_dev)
+        if ret != 0:
+            self.fail("Failed to prepare swap for pagesize test: %s %s" % (out, err))
+
+        # activation should fail because swap has different pagesize
+        with self.assertRaises(BlockDev.SwapPagesizeError):
+            BlockDev.swap.swapon(self.loop_dev)
+
+
 class SwapUnloadTest(SwapTest):
     def setUp(self):
         # make sure the library is initialized with all plugins loaded for other
-- 
2.17.1